A magnetic lead screw actuator is a linear actuator which can be used to convert a rotational movement into a linear movement. Magnetic lead screw actuators can be used in applications known to require a linear actuator. A magnetic lead screw actuator may be used as a damper in an active suspension system.
Suspension systems absorb and dissipate vibration inputs, thus decoupling a sprung element from impulse and vibration energy inputs experienced at an unsprung element. Suspension systems are employed on both stationary systems and mobile systems including passenger vehicles. Known suspension system elements include spring elements coupled in parallel and/or in series with damping elements, e.g., shock absorbers that include fluidic or pneumatic energy absorbing and dissipating features.
When employed on a vehicle system, suspension systems including springs and dampers are configured to coincidently provide performance characteristics related to passenger ride comfort, vehicle handling and road holding capability. Ride comfort is generally managed in relation to spring constant of the main springs of the vehicle, spring constant of passenger seating, tires and a damping coefficient of the damper. For optimum ride comfort, a relatively low damping force for a soft ride is preferred. Vehicle handling relates to variation in a vehicle's attitude, which is defined in terms of roll, pitch and yaw. For optimum vehicle handling, relatively large damping forces or a firm ride are required to avoid excessively rapid variations in vehicle attitude during cornering, acceleration and deceleration. Road holding ability generally relates to an amount of contact between tires and the ground. To optimize road handling ability, large damping forces are required when driving on irregular surfaces to prevent loss of contact between individual tires and the ground. Known vehicle suspension dampers employ various methods to adjust damping characteristics to be responsive to changes in vehicle operational characteristics, including active damping systems.
Active damping control benefits from precise measurement of displacement position and velocity of the active damping system. Known suspension systems employ various methods to determine displacement position and velocity including the use of potentiometers and linear transducers.